CV:Constant Voltage恒压

SMMB charger：Switch-ModeBattery Charger and Boost peripheral开关模式电池充电器和升压外围设备

OCV：Open circuitvoltage

EOC：End OfCharge充电结束

UUC：UnusableCapacity不可用电量

对应的源代码文件为\kernel\drivers\power\qpnp-vm-bms.c，高通QPNP电压模式的PMIC电池管理系统(Qualcomm'sQPNP Voltage-Mode(VM) PMIC Battery Management System)，提供接口给客户端来读取电池相关属性，它的主要功能是基于周期性采样VBAT(vattery voltage)来计算SOC(state ofcharge)

下面学习kernel\Documentation\devicetree\bindings\power\qpnp-vm-bms.txt

父节点需要的属性如下

见kernel\arch\arm\boot\dts\qcom\msm-pm8909.dtsi文件的pm8909_bms: qcom,vmbms节点

- compatible : Must be "qcom,qpnp-vm-bms" for the BM driver.

 

- reg              :Offset and length of the PMIC peripheral register map.

比如reg = <0x4000 0x100>;

---

- interrupts   : The interrupt mappings.

                The format should be

                <slave-id peripheral-idinterrupt-number>.

比如

interrupts =       <0x0 0x40 0x0>,

                  <0x00x40 0x3>,

                  <0x00x40 0x4>,

                  <0x00x40 0x5>;

---

- interrupt-names : names for the mappedbms interrupt

              Thefollowing interrupts are required:

              0: leave CV state离开恒压状态

              1: enter CV state

              2: good ocv generated

              3: ocv_thr

              4: fifo update

              5: fsm state changed

比如

interrupt-names = "leave_cv",

                "ocv_thr",

                "fifo_update_done",

                "fsm_state_change";

---

此外，可选的子节点可包含：

- qcom,batt-pres-status : A subnode with aregister address for the SMBB

              batteryinterface's BATT_PRES_STATUS register. If this node is

              added,then the BMS will try to detect offmode battery removal

              viathe battery interface's offmode battery removal circuit.

这是带有一个关于SMMB电池接口寄存器BATT_PRES_STATUS地址的子节点，如果增加了此节点，BMS将会尝试通过电池接口的offmode电池接插电路检测offmode电池接插

例如

qcom,batt-pres-status@1208 {

    reg= <0x1208 0x1>;

};

---

电池曲线：

- qcom,battery-data : A phandle to a nodecontaining the available batterydata

  profiles.See the batterydata bindings documentation for more

  details.

此节点的值是一个phandle，它指向一个包含有效电池曲线数据的节点，详见kernel\Documentation\devicetree\bindings\batterydata\batterydata.txt

在kernel\arch\arm\boot\dts\qcom\msm8909-qrd-skue.dtsi中定义

/ {
        qrd_batterydata:qcom,battery-data {
          qcom,rpull-up-kohm= <0>;

          qcom,vref-batt-therm= <1800000>;



          #include"batterydata-qrd-skue-4v35-2000mah.dtsi"

   };

};

&pm8909_bms {
       status= "okay";
       qcom,resume-soc= <95>;
       qcom,use-reported-soc;
       qcom,force-bms-active-on-charger;
       qcom,battery-data = <&qrd_batterydata>;

};

父节点需要的属性

- qcom,v-cutoff-uv : cutoff voltage wherethe battery is considered dead in

                     micro-volts(微伏).

关机电压，用于计算SOC，如修改关机电压，除了修改这里，还需要修改电池曲线数据的qcom,v-cutoff-uv，其实最好是用电池曲线数据里的。

比如qcom,v-cutoff-uv = <3400000>;

- qcom,max-voltage-uv : maximum voltage forthe battery in micro-volts.

电池最大的电压，单位为毫伏，比如qcom,max-voltage-uv =<4200000>;

- qcom,r-conn-mohm : connector resistancein milli-ohms.

连接器电阻，如qcom,r-conn-mohm = <0>;

- qcom,shutdown-soc-valid-limit : If theocv upon restart is within this

                     distanceof the shutdown ocv, the BMS will try to force

                     thenew SoC to the old one to provide charge continuity.

                     Thatis to say,

                            if(abs(shutdown-soc - current-soc) < limit)

                            thenuse old SoC.

如qcom,shutdown-soc-valid-limit =<100>;

- qcom,low-soc-calculate-soc-threshold :The SoC threshold for when

                     theperiodic calculate_soc work speeds u